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 A218220 Array a(n,m) read by antidiagonals where a(0,m)=a(1,m)=1 and a(n,m) = m*a(n-1,m)-a(n-2,m) for n>=2. 1
 1, 1, 1, 1, 1, -1, 1, 1, 0, -1, 1, 1, 1, -1, 1, 1, 1, 2, 1, -1, 1, 1, 1, 3, 5, 1, 0, -1, 1, 1, 4, 11, 13, 1, 1, -1, 1, 1, 5, 19, 41, 34, 1, 1, 1, 1, 1, 6, 29, 91, 153, 89, 1, 0, 1, 1, 1, 7, 41, 169, 436, 571, 233, 1, -1, -1, 1, 1, 8, 55, 281, 985, 2089, 2131, 610, 1, -1, -1, 1, 1, 9, 71, 433, 1926, 5741, 10009, 7953, 1597, 1, 0, 1, 1, 1, 10, 89, 631, 3409, 13201, 33461, 47956, 29681 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,18 COMMENTS Variant of A094954 and A162997. a(n,0) alternates 1,1,-1,-1,1,1,... a(n,1) alternates 1,1,0,-1,-1,0,... a(n,2)=1 a(n,3) is alternating fibonacci numbers. LINKS Table of n, a(n) for n=0..100. EXAMPLE 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,... 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,... -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,... -1, -1, 1, 5, 11, 19, 29, 41, 55, 71, 89,... 1, -1, 1, 13, 41, 91, 169, 281, 433, 631, 881,... 1, 0, 1, 34, 153, 436, 985,1926,3409,5608,8721,... -1, 1, 1, 89, 571,2089,5741,13201,26839,49841,86329,... -1, 1, 1, 233,2131,10009,33461,90481,211303,442961,854569,... CROSSREFS Cf. A218219. Sequence in context: A193518 A060176 A305297 * A247487 A010248 A325403 Adjacent sequences: A218217 A218218 A218219 * A218221 A218222 A218223 KEYWORD sign,tabl,easy AUTHOR Nico Brown, Oct 23 2012 STATUS approved

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Last modified February 27 19:38 EST 2024. Contains 370378 sequences. (Running on oeis4.)